Concentrating or separating of the values from soluble ores



United States Patent CONCENTRATING 0R SEPARATING OF THE VALUES FROM SOLUBLE ORES George E. Atwood and Douglas J. Boume, Carlsbad, N. Mex., assignors to Duval Sulphur & Potash Company, Houston, Tex., a corporation of Texas No Drawing. Application February 2, 1953, Serial No. 334,736

15 Claims. (Cl. 209-166) This invention relates to the concentrating or separating of the values from ores. More particularly it relates to flotation processes or modifications thereof wherein a mineral collector is employed.

This application is filed as a continuation-in-part of our co-pending application, Serial No. 278,314, filed March 24, 1952, now abandoned.

In the type of flotation process to which this invention is applicable, slimes are usually present in the flotation step and impair the efficacy of the reagent or agent which functions as the mineral collector. In those processes where extremely slimy pulps are encountered it is the general practice to include a desliming step for removing the slimes from the ore pulp prior to the passage of the pulp to flotation; however, even in these instances some slimes escape the removal step and pass to flotation so that the problem of their adverse effect upon the mineral collector is still present. To inhibit this adverse effect of slimes upon the collector during the flotation step it has been the common practice to employ auxiliary reagents and examples of such auxiliary reagents as starch and dextrin, with starch having perhaps the widest application throughout the mineral dressing industry.

The processes and methods of the present invention are the results of the discovery that the use of a polymer consisting principally of mannose units as an auxiliary reagent gives greatly improved yields as compared to other reagents in the auxiliary class, and it is, therefore, the general object of this invention to provide an improved method of separating the values from ores by flotation wherein a polymer consisting principally of mannose units, is employed as the auxiliary reagent.

As used herein the term polymer consisting principally of mannose units is intended to include those naturally occurring compounds such as mannogalactan and glucomannan, or any compound in which mannose units are predominant. For the sake of clarity, the description herein will refer to mannogalactan and its function as an auxiliary reagent, but it is to be understood that the invention is not limited to this specific compound.

The invention has been found particularly applicable to froth flotation processes but is, adaptable to other concentrating operations wherein a selective mineral collector is employed, i. e.. agglomeration processes.

A particular object of the invention is to provide an improved method of recovering sylvite ores wherein the usual collector is employed in the flotation step and also wherein mannogalactan is added to function as an auxiliary reagent.

Another obiect is to provide an improved flotation process employing a mineral collector and an auxiliary reagent which process effects maximum recovery of the valuable ore constituents with a minimum amount of said auxiliary reagent.

Mannogalactan occurs naturally in the seeds of many legumes, an example of which is the endosperm of the pod-bearing legume known as guar. It has been found that the mannogalactan occurring in guar seeds consists of approximately 67% mannose units and 33% galactose units. However, the proportion of mannose units to galactose units may vary from that of the guar seeds, depending upon the particular source of the material. Othercommon sources of mannogalactan suitable for the practice of the method herein disclosed are the seeds of thefollowing: carob bean, honey locust, flame tree, huizache, tara, (palo verde, and Kentucky coffee.

2,696,912 Patented Dec. 14, 1954 ICC Glucomannan is a reserve carbohydrate found in the corms of plants of the Araceae family and comprises a polymer of mannose and glucose units in the approximate proportion of two mannose units to one glucose unit.

It has been found that mannogalactan is eflicient as an auxiliary reagent when used in conjunction with mineral collectors, such as aliphatic amines and aliphatic soaps and it is believed that it has wide application in flotation processes employing such selective collectors.

The use of mannogalactan as an auxiliary reagent will be described herein as applied to the concentration of soluble potassium ores but the invention is not to be limited to this specific field of use.

In the concentration of soluble potassium ores, mannogalactan is several times as effective as starch, which is generally recognized as an efficient auxiliary, on the basis of equivalent yields. Maximum recovery of the sylvite can thus be effected with the use of a minimum amount of the auxiliary, whereby a substantial economic advantage is realized. Not only 'does the reduced amount of auxiliary provide an economic advantage solely from the cost standpoint but it also makes such auxiliary particularly useful in the usual closed system of operation. As is well known, it is highly desirable, in such closed system, to hold the quantity of the added reagents or collectors to a minimum to eliminate possible building-up of the added material which might interfere with overall operation; since mannogalactan is effective as an auxiliary reagent in minimum quantities, its use in the usual closed system is advantageous. A

' marked improvement in yield when using mannogalactan as the auxiliary is obtained with different types of mineral collectors.

To illustrate the advantages and improved results produced by the use of a polymer consisting principally of mannose units, such as mannogalactan, as the auxiliary, a series of comparative tests were conducted; such tests compare the recovery obtained when mannogalactan is used as the auxiliary to the recovery realized when potato starch is employed as the auxiliary. Potato starch was selected for the comparison because it is generally recognized as having highly efiicient qualities as an auxiliary reagent.

The tests which were made and the results of which are hereinafter fully set forth were confined to froth flotation of potassium chloride and sodium chloride from a sylvite ore of the Carlsbad, New Mexico, area. However, it is obvious that the invention is applicable to agglomeration processes.

It is well known that sylvite (potassium chloride) can be recovered from a pulp of the ore in a saturated solution of the soluble constituents of sylvite ore in accordance with concentration operations by using as a collector an aliphatic amine containing a straight chain hydrocarbon group, either saturated or unsaturated, or the salts of such amine resulting from their combination with water-soluble acids. The amines useful as collectors for sylvite include, but are not limited to, the following ali hatic primary amines: n-decylamine, n-undecylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, nheptadecylamine, n-octadecvlamine, n-octadecenvlamine. The foregoing primary amines contain a straight chain hydrocarbon group having from 10 to 18 carbon atoms but other amines containing a strai ht chain hydrocarbon group up to 22 carbon atoms would probably be suitable for the practice of this method.

The aliphatic amines may be added to the ore pulp in the form of the free base, or as the salts formed by their combination with acids. The amine collectors may be 'used individually or as mixtures, and the mixtures need not necessarily consist only of aliphatic primary amines or their salts but may also contain varying proportions of aliphatic secondary and tertiary amines or their salts, such as are commonly found in commercial products. For example, the collector may be an amine 3 low amine acetate sold under the trade name of Armac HTD by Armour & Company.

It is also well known that halite (sodium chloride) can be floated in this type of process by employing as a collector an aliphaticsoap.

Certain tests were conducted wherein the salts of aliphatic amines were used as the collector while additional testswere carried out using aliphatic soap as the collector.

In the-testsusing the salts of aliphatic amines for the recoveryof sylvite (potassiumchloride), the collectors selected were Armac TD andArmac HTD. These collectors were used in the. form of. an aqueous solution. The auxiliary reagents with the, exception of ilesmannan were used in the form of a brine sol; illesmannan was prepared as a water sol. The dispersion inthe sol is greatly enhanced by the addition of heat during its preparation, which in .turn markedly improves its auxiliary action. The test procedure was as follows:.

Thoroughly-mixed batches of. sylvinite ore from the Carlsbadarea were split into several 600-gram samples for use as feed; These samples were wet-ground to minus 14 mesh using a saturated KCl-NaCl brine as a carrier. The ground samples were partia ly deslimed by decantetion to a 60% pulp density. The auxiliary reagent was added to the above slurry and conditioned for 45 seconds. The. collector was then added and similarly conditioned for: 45 seconds. Thereagentized pulp was then added to a-Fagergren test cell where it was dilutedto approximately 20% solids. It was agitated for two minutes without air and then floated to the absence of mineral in the froth. I

In the following test data, which is self-explanatory, ArmacTD was employed as the collector:

Test I.--No Auxiliary, usingArmac TD Quantity Auxiliary 0. Collector 0.40 lb./ton ore.

Percent K20 Recovery Type Quantity Auxiliary. Collector 0.05'lb./to11 ore.

Mannogalactan (Guar) TD 0.40 lb./tn ore.

Armae Percent K iii) Test IV.Mann0galactan consumption vs. recovery using Armas TD Percent K 0 Percent K20 Recovery 26.5 59. 5 09. 2 ails 0.4 .8

Test V.Starcnconsumption vs. recovery using Arrnac T D Type Quantity Auxiliary Potato starch 0.20 lb./ton ore. Collector Armac TD 0.40 lb./ton ore.

Percent K20 Percent R20 Recovery Feed 26.5 Concentrate. 60. 1 34. 4 Tails 20. 5 65. 6

Test VI.'.S'tarc/1 consumption. vs. recovery using Armac'TD yp Quantity Auxiliary Potato Starch 0.40 lb./ton ore. Collector Armae TD 0:40 1b.!ton ore.

Percent K20 Percent K20 Recovery Test I illustrates that no recovery'wasobtained when no auxiliary reagent was employed.

In Test II, whereon 0.5 pound of mannogalactan per ton of ore was employed, recoverywas 33%.

In Test Employing the same collector reagent, TestV illustrates Recovery Test III.-Mannogalactan consumption vs; recovery using Armuc TD Percent K20 Percent K20 Recovery that when .20 pound potato starch per, ton of ore was employed, recovery was: only 34.4%; comparing this to the use of .20 pound mannogalactan per ton of ore (Test IV), it is evident that the mannogalactan is several times as eifective. Test VI increased the starch per ton of ore to .40 pound, and although this is double the amount of mannogalactan employed in Test IV, recovery is still less, being 97.8% as compared to 99.2% in Test IV.

The data shown in Tests I-VI, illustrate that mannogalactanis several times as effective as starch and obviously a considerably less amount of .mannogalactan need be employed for the same recovery which is particularly advantageous in closed systems. Mannogalactan has also been found superior to starch in that the froth characteristics are decidedly better, thereby reducing troublesome problems in the handling and pumping of concentrates. Since the froth "characteristics are improved, mannogalactan is of decided advantage in flotation processes regardless of the type of selective mineral collector employed.

In the following tests, Atmac was .usediasj' thecollector:

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Test VII.N auxiliary using Armac HT D T est X ll lannogalactan from tara using Armac TD Type Quantity Type Quantity Auxiliary Auxiliary Tara 0.251b./ton ore. Collector Armac HTD..-. 0.50lb./ton ore. Collector Armac TD.... 0.401b./ton ore.

Percent K Re- Percent K10 Percent K20 covers, 10 Percent K20 Recovery Feed 26. U Feed 27. 3 Concentrate. 0.0 59. 8 89. 4 Tails 26.0 100. 0 4. 9 10. 6

1 This test conducted on feed containing more clay than Tests I to X.

Test VIII .-.Junnogalactan using Armac H TD X Type Quantity Test II Glucomannan uslng Armac TD Auxiliary Mannogalactan (Guar).. 0.201b./ton ore. Type Quantity Collector Armac HTD... 0. 50 lb./ton ore.

Auxiliary Ilesmannan... 0.25 lb./ton ore. Percent K20 Percegggzo Re- Collector Armac TD 0.40 lb./ton ore.

Percent K O 0 Percent K20 Recover;

Test IX.Starch using Armac HDT Type Quantity Auxiliary Potato Starch... 0 201b./ton ore. Collector Armac HTD. 0 50 lbl/ton ore.

Percent K20 Re- Percent K20 covers,

Test VIII reflects that where .20 pound of mannogalactan per ton of ore was employed, recovery was 73%. A similar quantity of potato starch which was used in making Test IX shows recovery to be only 42.8%. These comparative tests clearly illustrate the higher efliciency of mannogalactan as the auxiliary reagent.

All of the foregoing tests with the difierent amine collectors illustrate that the superiority of mannogalactan is not confined to a particular class of aliphatic amines :3

but is useful with the saturated as well as the unsaturated members.

Other tests employing mannogalactan produced from honey locust, and tara as well as tests employing the glucomannan identified as ilesmannan, were conducted and the following test data illustrates the improved results obtained.

The higher efficiency of mannogalactan as an auxiliary reagent is not restricted to a particular type of collector reagent or to a particular flotation process. One method of concentrating the valuable constituents of soluble salt mixtures is to remove the sodium chloride impurity by froth flotation, using as a collector an aliphatic soap. The tests hereinafter outlined evidence the fact that improved results are obtained in processes of this type where mannogalactan is employed as the auxiliary reagent.

In the tests made using an aliphatic soap as the collector, the test procedure was as follows: Identical feed samples, consisting of 1000 grams of mixed sodium and potassium salts, were prepared. Said samples were dry ground to pass a 28 mesh sieve and to contain approximately 20% minus 200 mesh. The samples were pulped to density in a brine saturated with the major constituents of the feed and containing a soluble lead salt equivalent to two grams of lead per liter of brine. The auxiliary was added and the pulp conditioned for thirty seconds. Following this step, the pulp was transferred to a standard test cell where it was diluted with brine to approximately 35% solids. The soap collector was then added and flotation ofthe halite (sodium chloride) was commenced. Flotation continued to the absence of mineralized froth. Attention is directed to the fact that starvation reagent quantities were used in an effort to contrastl auxiliary power rather than to produce a commercial resu t.

Test XIII.N0 auxiliary using soup (principally pelurgonic acid) Type Quantity 0 0. .5% aliphatic acid 0.294 1b. dry soap] soap. ton ore.

Percent Nam Percent NaOl Type Quantity Auxiliary Potato Starch... 0.25 lb./ton ore. Collector aliphatic acid 0.294 lb./dry soap] soap. ton ore.

Percent NaCl Percent NaCl Recovery Residue 54. 6 80. 0

Test X V.Mann0galactan auxiliary using soap (principally pelargonic acid) Test X VI.N0 auxiliary using oleic acid soap Type Quantity Auxiliary C0llect0r 0 0. Oleic Acid Soap." 0.50lb,/t0n ore.

Percent NaOl Percent N8 Recovery Test X VII .Starch auxiliary using oleic acid soap Type Quantity Auxiliary Corn Starch 0.50 lb./ton ore. Collector Oleic Acid S0ap. 0.50 lb./ton ore.

Percent NaCl Percent NaC Recovery Test X VIII .-Mann0galactan auxiliary using oleic acidsoap p Quantity Auxiliary Mannogalactan 0.50 lbJton ore. Collector Oleic Acid Soap... 0.50 1b./ton ore.

Percent NaCl Percent NaCl Recovery as. s 85. s 22. 9

Residue In the foregoing Test XIII where no auxiliary was used, a recovery of 17.6% was. obtained. In Test XIV .25 pound of potato starch per ton of ore was employed and the result was only slightly improved since recovery was increased to When .25 pound of man ogalactan per ton of ore was used, as set forth in Test recovery was increased to 44.7%, thereby demonstrating that. t use o mannosalaetan presides. a d.

proven lent in yie d. Tests XVI, to XVIII demonstrate that mannogalactan increased recovery when used as an auxiliary with oleic acid soap.

To further illustrate. the higher eificiencies obtained whenusing apolymer. cons t n f p n p lly mannose units as the auxiliary reagent, the following tests are cited to indicate auxiliary action with the sulphate-type collectors inthe flotat on oibo sylvite and halite.

Test procedures for this group of experiments were the same asthose previously outlined for fatty acid soap flotation with the exception that where sylvite is the floated mineral the brine contained no lead.

The first of this series demonstrates the improvement obtained when using either mannogalactan or glucornannanwith a sulphated fatty ester in the flotation of halite from a potassium ore. The sulphated ester selected was Emery Industries Twitchell 7250.

Type Quantity Percent NaCl Percent NaCl ecovery Residue: 7

Test XX.-Starch auxiliary using Twitchell 7250 yp Quantity Auxiliary. Corn Starch 0.5 lb./ton ore. Collector Twitchell 7250. 6.0 lb./ton ore.

Percent NaCl Percent NaCl Recovery Test XXI.Mann0galactan auxiliary using Twitchell 7250 Type Quantity Auxiliary Mannogalactamn. 0.5 lb./ton ore. Collector Twitchell 7250 6.0 lb./ton ore.

Percent NaCl Test XXII.Gluc0mannan auxiliary using T witchell 7250 Percent NaCl Recovery In the foregoing tests, recovery was improved from 38.7% using no auxiliary, through 89.7% using starch, to 97.8% and 98.4% using mannogalactan and glucomannan respectively.

Additionally, this series of tests showed a marked improvement in froth characteristics when using the polymers consistingprincipally of mannose units.

The second, series of experiments with sulphate-type semeste s-emphasise. s9mtasr9iel. rpdust Qtene hich consists principally of sodium lauryl sulphate, to float the mineral sylvite from potassium ores.

Test XXlII.--N auxiliary using Drene ype Quantity Auxiliary.

0. 6.0 lb./ton ore.

I'ercent K Percent K20 Recovery T est XXI V.Starch auxiliary using Drene Type Quantity Corn Starch... 0.5lb./tou ore. Drene 6.0 lb./ton ore.

Percent K20 Percent K20 Percent K20 Percent K20 Recovery In Test XXIII, with no auxiliary reagent, there was no mineral collection. Test XXIV, using starch, effected flotation. However, Tests XXV and XXVI again demonstate the superiority of mannose polymers.

It is understood that the mannogalactan is used in the process in the usual well known manner of use of auxiliary reagents and it is, therefore, deemed unnecessary to outline in detail the introduction of the mannogalactan into the system since such introduction may be accomplished in various ways in accordance with procedures well known in the art. Any system of opera tion can be employed in utilizing the disclosures herein in commercial practice.

The invention has a wide field of application and the discovery of this new flotation auxiliary reagent has marked economical significance, not only in the concentration or treatment of soluble salts but also in other flotation processes where the use of an auxiliary reagent has been found beneficial.

Having described the invention, we claim:

1. The improvement in the method of separating valu able constituents from potassium ores which comprises subjecting the ore to a concentrating process employing a mineral collector, said improvement residing in, distributing in said ore during the concentrating p'rocess' a useful amount of an auxiliary reagent which is a polymer consisting principally of mannose units.-

2. The improvement in the method of separating valuable constituents from potassium ores which comprises subjecting the ore to a concentrating process employing a mineral collector, said improvement residing in, distributing in said ore during the concentrating process a useful amount of an auxiliary reagent which is a polymer containing mannose and galactose units.

3. The improvement in the method of separating valuable constituents trom potassium ores which comprises subjecting the ore to a concentrating process employing a mineral collector, said improvement residing in, dis tributing in said ore during the concentrating process a useful amount of mannogalactan to function as an auxiliary reagent.

4. The improvement in the method of separating valuable constituents from potassium ores by a flotation process employing a mineral collector, said improvement residing in distributing in the ore a useful amount of mannogalactan which functions as an auxiliary reagent.

5. The improvement in the method of concentrating sylvite from a sylvite ore in a pulp formed by suspending the sylvite ore in a saturated aqueous solution of the soluble ore constituents and conditioned with a selective mineral collector, said improvement residing in distributing in said pulp a useful amount of mannogalactan as an auxiliary reagent.

6. The improvement in the method of separating sylvite from'a pulp containing it which comprises subjecting said pulp to a concentrating process employing a collector selected from the group consisting of aliphatic amines and their salts formed by their combination with water soluble acids, which acids are relatively devoid of surface active properties, said improvement residing in distributing in said pulp a useful amount of mannogalactan to function as an auxiliary reagent.

7. The improvement in the method of concentrating sylvite from a sylvite ore in a pulp formed by suspending the sylvite ore in a saturated aqueous solution of the soluble ore constituents and conditioned with a collector selected from the group consisting of aliphatic amines containing a straight chain hydrocarbon group having from 10 to 22 carbon atoms, and their salts formed by their combination with water soluble acids, said improvement residing in distributing in said pulp a useful amount of an auxiliary reagent which is a polymer consisting principally of mannose units.

8. The improvement in the method of concentrating sylvite from a sylvite ore in a pulp formed by suspending the sylvite ore in a saturated aqueous solution of the soluble ore constituents and conditioned with a collector selected from the group consisting of the aliphatic amines containing a straight chain hydrocarbon group having from 10 to 22 carbon atoms, and their salts formed by their combination with water soluble acids, said improvement residing in distributing in said pulp a useful amount of mannogalactan as an auxiliary reagent.

9. The improvement in the method of separating potassium chloride from sylvite ore by froth flotation wherein the mixture of salts being slurried in brine is subjected to a flotation step in which an aliphatic soap is employed as the sodium chloride collector, said improvement residing in distributing in the brine slurry an auxiliary reagent which is a polymer consisting principally of mannose units.

10. The improvement in the method of separating valuable constituents from potassium ores by a flotation process wherein the ore is subjected to a flotation step in which an aliphatic soap is used as the collector, said improvement residing in distributing in the ore mannogalactan which functions as an auxiliary reagent.

11. The improvement in the method of separating sodium chloride from salt mixtures by froth flotation wherein the mixture of salts being slurried in brine is subjected to a flotation step in which an aliphatic soap is employed as the sodium chloride collector, said improvement residing in distributing in the brine slurry mannogalactan as an auxiliary reagent.

12. The improvement in the method of separating valuable constituents from potasium ores which comprises subjecting the ore to a concentrating process employing a mineral collector, said improvement residing in, distributing in said ore during the concentrating process a useful amount of mannogalactan which is produced from the endosperm of guar.

13. The improvement in the method of separating valuable constituents from potassium ores which comprises subjecting the ore to a concentrating process employing a mineral collector, said improvement residing in, distributing in said ore during the concentrating process a useful amount of mannogalactan which is produced from honey locust.

14. The improvement in the method of separating valuable constituents from potassium ores which cornprises subjecting the ore to a concentrating process employing a mineral collector, said improvement residing in, distributing in said ore during the concentrating process a useful amount of mannogalactan which isproduced from tara.

15. The improvement in the method of separating valuable constitutents from potassium ores which comprises subjecting the ore to a concentrating'process employing a mineral collector, said improvement residing in, distributing in said ore during the concentrating process a useful amount of glucomannan.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES ManufacturingChemist and Manufacturing Perfumer, July 1949, vol. 20, No. 7, pages 321-324; page 322 relied on. (Copy in Scientific Library.)

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1. THE IMPROVEMENT IN THE METHOD OF SEPARATING VALUABLE CONSTITUENTS FROM POTASSIUM ORES WHICH COMPRISES SUBJECTING THE ORE TO A CONCENTRATING PROCESS EMPLOYING A MINERAL COLLECTOR, SAID IMPROVEMENT RESIDING IN, DISTRIBUTING IN SAID ORE DURING THE CONCENTRATING PROCESS A USEFUL AMOUNT OF AN AUXILIARY REAGENT WHICH IS A POLYMER CONSISTING PRINCIPALLY OF MANNOSE UNITS. 